Bill Gates is known as a relentless — some might even say ferocious — competitor, so it’s not altogether surprising that he angled to take control of Microsoft, which dominated the desktop-software market for nearly two decades.

But Allen’s candid appraisal of his relationship with the man he thought he had a 50-50 agreement with shines new light on the intrigue at the highest levels of Microsoft as it grew to become a corporate giant.

If true, Allen’s account would upend key pillars of the conventional wisdom regarding Microsoft’s history. Many people believed that Allen’s growing distance from the company was prompted in large part by his battle with Hodgkin’s Disease in 1982, The Wall Street Journal noted of the memoir Wednesday.

But Allen writes that he felt alienated from Gates, because of the latter’s hard-driving and combative personal style.

“My sinking morale sapped my enthusiasm for my work, which in turn could precipitate Bill’s next attack,” Allen writes, according to the Journal.

“I had helped start the company and was still an active member of management, though limited by my illness, and now my partner and my colleague were scheming to rip me off,” Allen writes of Gates and Steve Ballmer. “It was mercenary opportunism, plain and simple.”

It’s not clear what Allen’s motivations were in writing the new book. With an estimated net worth north of $10 billion, he certainly doesn’t need the money.

A spokesperson for the Portfolio imprint of Penguin Group USA, which is publishing the book April 19, said Allen would not be doing interviews prior to that date.

At the end of the day, this is about the dirty laundry of two giant egos. However, it is important from a historical perspective. If Allen is really as aggrieved as he sounds, than it’s not surprising that he feels the need to set the record straight. Or that he would choose to do so with a publish date that is a mere 15 days after the 36th anniversary of the founding of Microsoft.

Allen’s book is not, however, the final record of the history of Microsoft. It will be up to future — impartial — historians to fashion a more complete picture, and try to separate fact from fiction and faulty memory.

Photo: Bill Gates, left, chats with Portland Trail Blazers owner and former business partner Paul Allen during a March 2003 game between the Blazers and Seattle SuperSonics in Seattle. (Elaine Thompson/AP)